Hydrogen sulfide, a common byproduct of oil and gas development, is an explosive gas, similar in toxicity to cyanide, that attacks the nervous system. Recognizable in trace amounts by its distinctive rotten egg odor and often referred to as "sour gas," it can be lethal.
The so-called "safe" exposure limits for hydrogen sulfide are based on the theoretical amount a healthy, 160-pound male worker could tolerate. The H2S occupational limit is 10 parts per million (ppm) over a portion of each workday.
In the real world, people do not react uniformly to H2S. Among the most vulnerable are adults with chronic illnesses, and children. Even someone with a cold has a weakened immune system, and consequently a lower tolerance for H2S exposure.
The Michigan Department of Community Health recommends an exposure limit for the general population of 0.01 to 1 ppm, although no standard is yet in place. In comparison, California has a public exposure limit of 0.03 ppm, and Elberta, Canada, has a limit of 0.02 ppm. Even at these levels, however, some people can experience headaches and other symptoms of H2S poisoning.
At very low levels H2S can deaden nerve endings, which means that an exposed person is unable to detect the rotten-egg odor to know that he or she is at serious risk. Exposure to H2S causes lung, eye, and skin irritation, nausea, light-headedness, and disorientation. As concentrations increase, so do the severity of the injuries, including unconsciousness and the risk of death.
What you can do
• The Institute and the H2S Committee are continuing their investigation of hydrogen sulfide releases. If you know about more incidents, contact Keith Schneider at the Institute (616-882-4723), or Dana Schindler of the H2S Committee (616-723-9766).
• The Department of Environmental Quality is starting to respond to citizens who are insisting that the state protect the public from harmful exposure to hydrogen sulfide.
Concerned citizens want to make sure that the DEQ follows through with the most thorough and effective safety program possible. It is vital that state regulators not stop with a few new rules, but establish comprehensive H2S regulations that ensure public safety.
You can add your voice to support the statewide campaign for public health enforcement by calling or writing:
Hal Fitch, Chief of the DEQ Geological Survey Division, P.O. Box 30473, Lansing, MI 48909-7973, Tel. 517-334-6923
Gov. John Engler, State Capitol, P.O. Box 30013, Lansing, MI 48909, Tel. 517-373-3400
Your state representatives (for addresses see the Bulletin Board on page 24)